Applicant claims, under 35 U.S.C. xc2xa7119, the benefit of priority of the filing date of Dec. 16, 2000 of a German patent application, copy attached, Serial Number 100 63 013.8, filed on the aforementioned date, the entire contents of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an angle measuring system, having a stator and a rotor for measuring the angular position between a stationary object and an object which is rotatable with respect to it, a coupling for the stator and the stationary object and a mounting element with an expansion element on the coupling. The present invention further relates to a method for mounting the angle measuring system on a drive mechanism.
2. Discussion of Related Art
Couplings for the connection, fixed against relative rotation, of a scanning device, a housing or an installation flange of the angle measuring system with a stationary element of a drive mechanism, are employed in angle measuring systems.
An angle measuring system with such a coupling is described in U.S. Pat. No. 5,758,427, the entire contents of which are incorporated herein. There, the shafts of the angle measuring system and the drive mechanism are connected with each other rigidly without an adjustment possibility, and the stators are connected with each other resiliently, but fixed against relative rotation, by a parallel guide device. Tumbling movements of the shafts are optimally compensated by two parallel guide devices arranged perpendicularly with respect to each other, without the stators being able to twist with respect to each other. In this case, the coupling does not perform rotary movements around the axis of rotation to be measured. Fastening of the coupling on the drive mechanism is provided by radial clamping between the coupling and a stationary portion of the drive mechanism. For this purpose, the coupling is preferably fastened on a ring-shaped mounting element, and the mounting element can be radially expanded by an expansion element and can therefore be clamped on a tube-shaped inner surface of the drive mechanism. The expansion element is aligned parallel with respect to the axis of rotation and is accessible. It is therefore necessary to make a relatively large clear space available for operating the expansion element.
It is therefore an object of the present invention to create an angle measuring system, which can be mounted in an extremely space-saving and simple manner, and assures exact coupling as well.
This object is attained by an angle measuring system that includes a stator and a rotor for measuring an angular position between a stationary first object and a second object, which is rotatable about an axis of rotation. A coupling couples the stator to the stationary first object so that the stator is fixed against relative twisting, but is also radially and/or axially resilient. A mounting element that clamps a face of the stationary first object by expanding in a radial direction with respect to the axis of rotation. An expansion element that interacts with the mounting element so as to cause the expanding in a radial direction and a screw that actuates the expansion element, wherein the screw is screwed into the stationary first object.
It is further intended to disclose a method for mounting an angle measuring system on a drive mechanism, which is simple to perform.
This object is attained by a method for mounting an angle measuring system to a drive mechanism that includes providing a drive mechanism that has a stationary first object and a first shaft that rotates about an axis of revolution and providing an angle measuring system that has a stator and a second shaft for measuring an angular position between the stationary first object of the drive mechanism and the second shaft of the drive mechanism. Fastening a coupling to the stator of the angle measuring system and fastening the coupling to the stationary first object of said drive mechanism via a mounting element so that the coupling is fixed against relative twisting, but is radially and/or axially resilient. Clamping the mounting element on an interior face of the first stationary object of the drive mechanism by inserting an expansion element into the stationary first object of the drive mechanism so as to cause a radial expansion of the mounting element so as to be fixed against relative rotation. Connecting the second shaft of the angle measuring system to the first shaft of the drive mechanism so as to be fixed against relative rotation.
The advantages which can be achieved by the present invention particularly lie in that the angle measuring system can be mounted simply and in a space-saving manner. The radial, and particularly the axial production tolerances of the elements needed for mounting can be relatively large. Since the axial mounting position is not already determined during the production, it is possible to mount angle measuring systems with a stator without a bias in the axial direction on a drive mechanism by means of a coupling. The accuracy of the angle measuring system is increased by this.
Further advantages, as well as details of the present invention, ensue from the following description of a preferred embodiment represented in the drawings.